A variational study of the periodic Bloch wall is carried out. It is found that the periodic Bloch wall is energetically favorable only if the anisotropy constant of the material is smaller than a critical value; otherwise, the ordinary Bloch wall is energetically favored. Computations of the appropriate lengths are carried out, and the results agree fairly well with those obtained by Shtrikman and Treves for small values of the anisotropy constant.